For many years, the value of vital wheat gluten extracted from wheat flour or berries has been recognized, primarily for its natural protein value for food products, and for its physical and chemical properties, when hydrated, of increasing the viscosity of, for example, flour batters and substantially improving batter adhesion; and, in meat and poultry products and the like, for adhesively binding, extending or filling, and, indeed, providing a chewy texture.
Various processes have been developed for deriving the vital wheat gluten from wheat flour or berries, including the "dough" or "Martin" process in which hydrated and kneaded flour is formed into a cohesive elastic dough and is continuously washed to elute the starch grandules, or to screen out the starch liquors. Illustrative examples of techniques are described in U.S. Pat. Nos. 3,790,553; 3,851,085; and 4,132,566.
Until the discovery underlying the present invention, it is believed that uses of vital wheat gluten have had to be confined to applications that can tolerate its highly viscoelastic putty-like dough properties, namely, as in an additive in baking batters, and for meat, fish and poultry products where the addition of the gluten provides "valuable binding, adhesion, emulsification and water binding qualities" (Midwest Grain Products [Kansas] bulletin, "Challenging The Eighties", pages 32-35).
The putty-like, highly cohesive and non-textured properties in the hydrated gluten solid or massive "dough" have relegated hydrated vital wheat gluten to uses just as a binder or "glue"-like additive where it is physically intermixed and visually lost in the main product or ingredients. The total lack of texture let alone lack of open fiber-like texture and appearance, have no theretofore made it even a serious candidate as the primary constituent for a close analog for ground meat; and the high sticky viscoelastic properties further distant it from the tender fiber-layer taste sensation and cutting characteristics of, for example, a meat hamburger.
In accordance with basic discoveries made in achieving the present invention, however, a technique was surprisingly found radically and permanently to alter or transform both the physical and chemical properties of vital wheat gluten, particularly when hydrated, amazingly to change the physical characteristics from a clump of tough stretchable untextured "putty" to layered aerated loosely packed fiber strand textured structures, closely and substantially indistinguishably simulating the texture of ground beef or other meat; and chemically to denature the protein and otherwise suppress the activity of the originally high viscoelasticity of the gluten, just retaining enough to enable the strands to stray together in an analogous way to ground beef and the like--and with substantially identical physical appearance and mouthfeel, chew and taste sensation.
To achieve this remarkable transformation of normal physical and chemical properties, long thought to be inherent in hydrated vital wheat gluten, moreover, it was necessary to go in a direction absolutely contraindicated in this art. This art had thought that "gluten can sustain its unique properties when subjected to heat, unlike other hydrated proteins which undergo substantial changes when heated to critical temperatures" ("Challenging the Eighties", supra, page 34). Under the discovery of the present invention, quite to the contrary, it has now been found how to condition and subject the hydrated gluten to heat to achieve very substantial permanent changes in both chemical and physical characteristics that indeed give rise to the novel results of this invention.
In view of this surprising transformation, moreover, for the first time, vital wheat gluten can be used as the principal ingredient itself in producing very close wheat analogs to ground meats, hamburgers, sausages, and the like.